The move to open embassies is one of the most important steps in establishing a different relationship with Cuba although it is likely to take much longer to end most aspects of the commercial embargo that remains in place.

The negotiations between Washington and Havana surrounding the opening of embassies have focused on the sorts of travel restrictions that American diplomats will face and their ability to meet dissident Cubans. Mr Kerry will probably come in for strong criticism in Congress if the state department has signed up to considerable limitations on their freedom of movement.

Although the US does not have an embassy in Havana, it does have a large “interests” section that handles consular and other issues in Cuba.

However, there is still considerable resistance in Congress, especially from a group of influential Cuban American politicians. Marco Rubio, the Florida senator and Republican presidential candidate, has promised to try to block the nomination of a US ambassador to Cuba unless Havana substantially improves its human rights record.

That opposition in Congress has made the administration wary of pushing for substantial lifting of the broad sanctions regime on Cuba. Instead, Mr Obama has used executive orders to make it easier for Americans to visit the island and for companies in sectors such as telecoms and the internet to do business in Cuba, arguing that their services could help encourage political liberalisation.

Mr Obama hinted at the new announcement when on Tuesday he met Brazilian President Dilma Rousseff at the White House. Thanking her for Brazil’s support for “our new opening toward Cuba”, Mr Obama added that “Brazil’s leadership in the region, as well as its own journey to democracy and a market economy, can make it an important partner as we work to create more opportunities and prosperity for the Cuban people”.